1. Field of the Invention
At least one embodiment of the present invention is directed to the field of stents and stent delivery systems, and more particularly to systems for the treatment of a bifurcation of a passage and/or ostium of vessel.
2. Description of the Related Art
Stent systems are widely used in the treatment of stenoses. Intravascular stents are used in coronary, renal, and carotid arteries, for example, to maintain an open passage through the artery. In patients whose coronary heart disease consists of focal lesions, stents have proven effective. For example, where only a single coronary artery is clogged or where there are short blockages in more than a single artery, stents have been used with a great amount of success. An intravascular stent may be positioned in a clogged artery by a catheter and is often set in place by inflating a balloon upon which the stent is mounted. This expands the diameter of the stent and opens the previously clogged artery. The balloon is then deflated and removed from the patient while the stent retains an open passage through the artery.
It is recognized, however, that a stent can be deployed in manners other than inflating and deflating a balloon. For example, self-expanding stents have been developed in which a cover is removed from over a stent, thereby allowing the stent to deploy or spring into place. It is also contemplated that other deployment mechanisms or means may be used or developed to advantageously deliver and deploy a stent in position.
Nevertheless, a need still exists for properly delivering and locating a stent at a bifurcation. Although efforts have been made to use a stent at bifurcations, these sites have previously been inadequately treated by a stent. For example, U.S. Pat. No. 5,749,825 is representative of a catheter system that treats stenoses at an arterial bifurcation. The disclosure of U.S. Pat. No. 5,749,825 is hereby incorporated by reference.
Delivery of a stent to a vessel bifurcation will often employ a pair of guidewires (a primary, or main-branch, guidewire positioned in the main branch of the vessel and a secondary, or side-branch, guidewire advanced into the side branch vessel of the bifurcation) upon which the delivery catheter is advanced. The divergent paths of the guidewires at the vessel bifurcation aid in orienting the delivery catheter such that the side branch opening of the stent to be delivered is properly aligned with the side branch vessel.
One of the problems encountered with placing a stent in a bifurcation is the potential for the guidewires to become twisted and/or knotted. As a catheter is advanced along the guidewires the catheter may push the crossings of the guidewires all the way to vessel bifurcation resulting in an entanglement which prevents the catheter from being advanced beyond the bifurcation and preventing proper alignment of the stent to be delivered.
Thus, a need exists for a system which reduces wire crossing during the advancement of a stent delivery catheter.
All US patents and applications and all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety.
Without limiting the scope of the invention a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below.
A brief abstract of the technical disclosure in the specification is provided as well only for the purposes of complying with 37 C.F.R. 1.72. The abstract is not intended to be used for interpreting the scope of the claims.